In the flight of a missile, such as an aerospace vehicle, the launch trajectory is extremely important. A critical factor in this part of the flight is the propulsion system. Its performance can be measured in many ways using on board instruments for sensing pressure, temperature, fuel flow, etc. The most direct method for measuring the performance of the engine is to measure the acceleration which it produces on the vehicle. Conventional sensing methods require precise and complex mechanisms to develop a force signal proportional to the acceleration and to transmit this signal to the system, usually as an electrical signal. Precision pivots and flexures are needed together with bulky and heavy electrical transducers to read the signal.